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<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_typetraits.reference.add_lvalue_reference"></a><a class="link" href="add_lvalue_reference.html" title="add_lvalue_reference">add_lvalue_reference</a>
</h3></div></div></div>
<pre class="programlisting"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">add_lvalue_reference</span>
<span class="special">{</span>
   <span class="keyword">typedef</span> <em class="replaceable"><code>see-below</code></em> <span class="identifier">type</span><span class="special">;</span>
<span class="special">};</span>

<span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">using</span> <span class="identifier">add_lvalue_reference_t</span> <span class="special">=</span> <span class="keyword">typename</span> <span class="identifier">add_lvalue_reference</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">type</span><span class="special">;</span> <span class="comment">// C++11 and above</span>
</pre>
<p>
        <span class="bold"><strong>type:</strong></span> If <code class="computeroutput"><span class="identifier">T</span></code>
        names an object or function type then the member typedef <code class="computeroutput"><span class="identifier">type</span></code>
        shall name <code class="computeroutput"><span class="identifier">T</span><span class="special">&amp;</span></code>;
        otherwise, if <code class="computeroutput"><span class="identifier">T</span></code> names a type
        <span class="emphasis"><em>rvalue reference to U</em></span> then the member typedef type shall
        name <code class="computeroutput"><span class="identifier">U</span><span class="special">&amp;</span></code>;
        otherwise, type shall name <code class="computeroutput"><span class="identifier">T</span></code>.
      </p>
<p>
        <span class="bold"><strong>C++ Standard Reference:</strong></span> 20.7.6.2.
      </p>
<p>
        <span class="bold"><strong>Header:</strong></span> <code class="computeroutput"> <span class="preprocessor">#include</span>
        <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">type_traits</span><span class="special">/</span><span class="identifier">add_lvalue_reference</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
        or <code class="computeroutput"> <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">type_traits</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
      </p>
<div class="table">
<a name="boost_typetraits.reference.add_lvalue_reference.examples"></a><p class="title"><b>Table 1.12. Examples</b></p>
<div class="table-contents"><table class="table" summary="Examples">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>
                <p>
                  Expression
                </p>
              </th>
<th>
                <p>
                  Result Type
                </p>
              </th>
</tr></thead>
<tbody>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">add_lvalue_reference</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;::</span><span class="identifier">type</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="keyword">int</span><span class="special">&amp;</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">add_lvalue_reference</span><span class="special">&lt;</span><span class="keyword">int</span>
                  <span class="keyword">const</span><span class="special">&amp;&gt;::</span><span class="identifier">type</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="keyword">int</span> <span class="keyword">const</span><span class="special">&amp;</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">add_lvalue_reference</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">*&gt;::</span><span class="identifier">type</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="keyword">int</span><span class="special">*&amp;</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">add_lvalue_reference</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">*&amp;&gt;::</span><span class="identifier">type</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="keyword">int</span><span class="special">*&amp;</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">add_lvalue_reference</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&amp;&amp;&gt;::</span><span class="identifier">type</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="keyword">int</span><span class="special">&amp;</span></code>
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <code class="computeroutput"><span class="identifier">add_lvalue_reference</span><span class="special">&lt;</span><span class="keyword">void</span><span class="special">&gt;::</span><span class="identifier">type</span></code>
                </p>
              </td>
<td>
                <p>
                  <code class="computeroutput"><span class="keyword">void</span></code>
                </p>
              </td>
</tr>
</tbody>
</table></div>
</div>
<br class="table-break"><p>
        <span class="bold"><strong>Compiler Compatibility:</strong></span> All current compilers
        are supported by this trait.
      </p>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 2000, 2011 Adobe Systems Inc, David Abrahams,
      Frederic Bron, Steve Cleary, Beman Dawes, Glen Fernandes, Aleksey Gurtovoy,
      Howard Hinnant, Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Alexander
      Nasonov, Thorsten Ottosen, Roman Perepelitsa, Robert Ramey, Jeremy Siek, Robert
      Stewart and Steven Watanabe<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
      </p>
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